2.7 Cammed m20 feels slow

[Lower_E30]

Hey, i need some help from a m20 guru

Here are the specs on my engine :

• M20 2.7l •

-From a m20b25 engine
- 325i pistons
- 325e rods
- 325e crank
- Block machined down approx 2mm *
- Adjustable cam gear
- Stock head gasket
- 272° Shrick cams
- Supersprint replica headers > stock 325i exhaust, cats removed
- M30 AFM mated to stock airbox w/intake funnel, drilled lower box, stock filter
- 19lb injectors from M30
- polished throttle body
- MarkD 93 octane chip 7k rpm limit
- 12lb custom flywheel (made from a 2002 flywheel, lightened, and 325i ring gear pressed on)


But i barely pull away from a stock m20, which seems odd.
The adjustable cam gear is set at the stock position ( middle ) , im wondering if i should try and retard it a bit ?
Any ideas are welcomed

[digger]

firstly how optimised in the tune? M30 AFM, stroker, cam, will likely not want a std MarkD chip for a m20b25. have you got a wide band?

id be talking to SSSQuid they have chips for M30AFM or getting a custom tune/MS PNP. i wouldnt be moving the cam timing around unless you know the fuelling and ignition timing are pretty close

what do you get with a cranking compression test as a reference to compare to a stock b25?

[Lower_E30]

Tune isnt optimized for the cams, i will order the SSSquid one. I dont have the compression numbers with me, but ill see if i can find them or i'll redo the test. As for the wideband i do not have one.

as for the cam timing, which way is advance and which way is retard, i don't have markings on my cam gear. Im think turning the engine clockwise will retard ?

[digger]

Tune isnt optimized for the cams, i will order the SSSquid one. I dont have the compression numbers with me, but ill see if i can find them or i'll redo the test. As for the wideband i do not have one.

as for the cam timing, which way is advance and which way is retard, i don't have markings on my cam gear. Im think turning the engine clockwise will retard ?

tell him what the specs are he might tailor some things to suit better than a "regular" chip.

advancing the cam means one of the following depending what way you choose to move the engine (from cam or crank)

a) if you keep crank fixed rotate the cam clockwise, 2 degrees on cam is a 4 degree advance at crank, this means the inner part of the adjustable gear moves CW.
b) if you keep cam fixed the crank goes CCW. this means the outer part of the cam gear that belt attaches to moves CCW

retarding is the opposite

dont turn cam bolt CCW as you can loosen it, also make sure the pistons and valves wont touch

[Lower_E30]

My compression test results were 160-165 all around. I did the test with a cold engine, should redo it when warm to be more precise.

I advanced the timing a few degrees, halfway between center and max advanced, idle seems a bit rougher but i do see a big gain on acceleration. I should be getting a new o2 sensor tomorow.

[digger]

My compression test results were 160-165 all around. I did the test with a cold engine, should redo it when warm to be more precise.

I advanced the timing a few degrees, halfway between center and max advanced, idle seems a bit rougher but i do see a big gain on acceleration. I should be getting a new o2 sensor tomorow.

those compression results are a little low for a 2.7L with decked head so the cam timing does seem perhaps slightly retarded so i think the advance is the right direction to move.

that sounds like a massive amount of advance you have dialled in though, normally you would need about 2-3* on the cam (4-6* on crank) most gears allow a huge variation that isnt needed

[Lower_E30]

Thanks for the help, ill bring it back a bit